The present disclosure relates to a respiratory waveform (respiration waveform) drawing (graphing) system configured to draw (graph) a respiratory waveform of a subject on the basis of variation in the position of center of gravity of the subject and a biological information monitoring system configured to monitor a biological information of the subject on the basis of the variation in the position of the center of gravity of the subject.
Biological information of a subject (human subject, that is, a person being monitored) is one of important pieces of information for knowing the physical condition (body condition) of a patient or a care receiver in the sites of the medical treatment and the care. For example, respiratory condition of the subject can be grasped and utilized to grasp and improve (alleviate) the symptoms of, for example, the sleep apnea syndrome (SAS) and the snore.
It has been suggested that load sensors are arranged under legs of a bed to measure the respiratory condition of a subject on the basis of measured values of the load sensors (Japanese Patent No. 4883380). Further, it has been also suggested that load detectors are arranged under legs of a bed to obtain (acquire) the movement of the center of gravity of a subject living body on the bed so that the respiratory movement (breathing movement) and the heartbeat movement of the subject living body are obtained on the basis of the movement of the center of gravity (Japanese Publication of Examined Patent Application No. 61-24010).